In general, the camshaft device is a component in charge of opening/closing of an intake valve and an exhaust valve, conforming to the rotation of an internal combustion engine, and may include: a shaft functioning as a rotation axis; a cam lobe for adjusting a stroke, that is, the timing and length of opening/closing the intake valve and the exhaust valve of the engine; and a journal bearing functioning as a rotating stator.
Only a slight change in the curve of such a camshaft lobe causes a change in the opening/closing timing or the lift of each valve, and thereby affects the performance of the engine. Therefore, the lobe and the shaft in related arts mainly employ an iron-based material such as cast iron or cast steel which can secure durability even under a long-term use.